【Q&A Question 011】2016.05.01
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This post was last edited by liuquan1100 on 2016-5-2 00:29. [Q&A Question No. 011] May 1, 2016: What is the difference between cold oil pumps and hot oil pumps? What should be noted during the inspection? The answer key will be available after responding; scoring is based on answering the key points. A pump in which the temperature of the medium being transported is generally above 200 degrees is called a hot oil pump. The hot oil pump has high-quality materials; its supports and other accessories require water cooling, and the pump needs to be warmed up. It is necessary to pay attention to whether the cooling water and seal flushing systems are operating properly, as well as whether the warm-up lines for the backup pumps are in use.
What are the eight key differences between cold oil pumps and hot oil pumps? 1. Pumps used at temperatures below 200 degrees Celsius are cold oil pumps, while those used at temperatures above 200 degrees Celsius are hot oil pumps. 2. Ordinary hot oil pump sealing mechanisms are filled with seal oil, whereas cold oil pumps are not. 3. The pump body of the hot oil pump is of vertical segmented design, while that of the cold oil pump is of horizontal split design. Some hot oil pumps have a structure to prevent the movement of the pump’s centerline. 4. The clearance of the hot oil pump ring is large. The cold oil pump is smaller. 5. Heat oil pumps are usually made of carbon steel or alloy steel, while cold oil pumps can be made of cast iron. 6. The hot oil pump needs to be preheated before starting, but this is not necessary for the cold oil pump. 7. The supports, bearing housings, and mechanical seals of the hot oil pump all require water cooling, whereas this is not necessary for the cold oil pump. 8. The model of hot oil pumps is generally indicated by the letter R, while cold oil pumps are indicated by the letter J. The clearance standards for hot oil pumps should be set more generously than those for cold oil pumps, in order to avoid wear caused by thermal expansion. It is best to carry out alignment and other adjustments after the hot oil pump has been preheated.
What are the eight key differences between cold oil pumps and hot oil pumps? 1. Pumps used at temperatures below 200 degrees Celsius are cold oil pumps, while those used at temperatures above 200 degrees Celsius are hot oil pumps. 2. Ordinary hot oil pump sealing mechanisms are filled with seal oil, whereas cold oil pumps are not. 3. The pump body of the hot oil pump is of vertical segmented design, while that of the cold oil pump is of horizontal split design. Some hot oil pumps have a structure to prevent the movement of the pump’s centerline. 4. The clearance of the hot oil pump ring is large. The cold oil pump is smaller. 5. Heat oil pumps are usually made of carbon steel or alloy steel, while cold oil pumps can be made of cast iron. 6. The hot oil pump needs to be preheated before starting, but this is not necessary for the cold oil pump. 7. The supports, bearing housings, and mechanical seals of the hot oil pump all require water cooling, whereas this is not necessary for the cold oil pump. 8. The model of hot oil pumps is generally indicated by the letter R, while cold oil pumps are indicated by the letter J. When inspecting hot oil pumps, emphasis should be placed on checking the oil seals and mechanical seals.
1. The materials used for the pumps differ: hot oil pumps are made of carbon steel or alloy steel, with their pump supports being cooled by circulating water, whereas cold oil pumps are made of cast iron, and their pump supports do not require cooling. 2. The pump models are denoted differently: hot oil pumps are indicated by the letter R, while cold oil pumps are indicated by J. 3. The medium temperature of the pump varies: pumps operating at temperatures below 200°C are cold oil pumps (20–200°C), while those operating at temperatures above 200°C are hot oil pumps (200–400°C). 4. When in standby mode, the hot oil pump needs to be preheated, while the cold oil pump does not require preheating.
1. Oil pumps with an operating temperature below 200 degrees Celsius are considered cold oil pumps, while those with a temperature above 200 degrees Celsius are hot oil pumps. 2. Ordinary hot oil pump sealing mechanisms are filled with seal oil, whereas cold oil pumps are not. (Nowadays, series sealing or double-end face sealing is generally used.) 3. The pump body of hot oil pumps is of vertical segmented design, whereas the pump body of cold oil pumps is of horizontal split design. Some hot oil pumps have a structure to prevent the movement of the pump’s centerline. 4. The clearance of the hot oil pump ring is large. The cold oil pump is smaller (taking thermal expansion into account). 5. Heat oil pumps are usually made of carbon steel or alloy steel, while cold oil pumps can be made of cast iron. 6. The hot oil pump needs to be preheated before starting, but this is not necessary for the cold oil pump. 7. The supports, bearing housings, and mechanical seals of the hot oil pump all require water cooling, whereas this is not necessary for the cold oil pump. 8. The model of hot oil pumps is generally indicated by the letter R, while cold oil pumps are indicated by the letter J. When inspecting hot oil pumps, emphasis should be placed on checking the oil seals and mechanical seals.
When pumping oil, the oil pump must be isolated from the atmosphere and kept sealed; its sealing components have varying heat resistance levels, which affects the sealing performance at different temperatures. The selection of accessories also needs to take into account the effects of thermal expansion and contraction. Generally, high-temperature oil pumps require heat-resistant seals and components, while cold oil pumps allow for lower requirements regarding the heat resistance of materials.
The medium temperatures are different； The materials of the pumps are different ； The steps to enable are different
Oil pumps with an operating temperature below 180 degrees Celsius are considered cold oil pumps, while those with a temperature above 220 degrees Celsius are hot oil pumps. Before switching on the hot oil pump, check whether it has been properly preheated; turn off the preheating line before starting the hot oil pump. For the cold pump, just perform the regular checks before turning it on!
Difference: 1. It is used to transport media at temperatures above 200 degrees Celsius in the case of heat pumps； Pumps used to transport media at temperatures below 200 degrees Celsius are known as cold pumps ； 2. The material of the mechanical seal for hot oil pumps is of higher quality than that used in cold oil pumps ； 3. The clearance of the ring at the hot oil pump inlet is larger than that of the cold oil pump ； 4. The hot oil pump is equipped with a preheating line, while the cold oil pump does not. Inspection notes: 1. Before starting the hot oil pump, the preheating rate should not exceed 50 degrees Celsius per hour; pay attention to the effectiveness of the preheating ； 2. Lubricant quality, level ； Bring water or not ； 3. Preparation status of standby pump ； 4. Is the cooling water flowing smoothly? ； 5. Leakage situation
A pump in which the temperature of the medium being transported is generally above 200 degrees is called a hot oil pump. The hot oil pump has high-quality materials; its supports and other accessories require water cooling, and the pump needs to be warmed up. It is necessary to pay attention to whether the cooling water and seal flushing systems are operating properly, as well as whether the warm-up lines for the backup pumps are in use.